98 University (eological Survey of Kansas. 
Thickness.—The Chanute shales vary in thickness from 25 
feet to 100 feet. Their greatest thickness is on the south where 
apparently they coalesce with the shales above, as will be ex- 
plained in discussing the Iola limestone. To the northeast they 
gradually decrease in thickness, reaching a total of about 25 
feet at Kansas City, where they are well exposed in the bluffs 
along the Missouri river, Turkey creek and the Kansas river. 
Area.—The Chanute shales cover a zone wide at the south 
and growing narrow to the north. In the vicinity of Chanute, 
Urbana and Neodesha this zone is about nine miles wide, while 
at Kansas City it is a mere line in the almost vertical bluff. 
Its location can be seen at a glance on the surface map, VIIa, 
VIIb and VIIc, and on the county maps for Neosho, Allen, Wil- 
son and Montgomery counties, herewith included, where it oc- 
cupies a space between the two enclosing limestones. 
Characteristics.—The Chanute shales are exceedingly vari- 
able in character. Around Chanute they are a fine clay shale, 
excellently adapted for making brick, tile and pottery. Just 
east of the Neosho river, at Chanute, a sandstone appears 
which constitutes the main mass of the hills and is the exact 
equivalent of the clay shales only a few miles to the west. This 
rapid changing of shales to sandstone and then back again is 
very characteristic of the Chanute shales throughout the 
greater part of their extent. In the vicinity of Independence 
they appear principally as a sandstone, and the rich buff iron- 
stained soft sandstone of that place is the stratigraphic equiva- 
lent of the Chanute shales farther to the north. In places they 
grade over to rich bituminous shales carrying thin beds of 
coal, of little if any commercial value excepting in the vicinity 
of Thayer, where the coal reaches from 18 to 20 inches in 
thickness, and for more than twenty years has been mined to 
supply the local trade. 
Iola Limestone.4? 
The name Iola limestone is here used to designate the large 
and prominent limestone lying first above the Chanute shales. 
It was first introduced by Haworth and Kirk in 1894, and has 
been used continuously and without question by every one 
writing on the geology of this part of the state from that time 
to the present. 
Thickness.—The Iola limestone at Iola is 40 feet thick. To 
42. Haworth, Prof. Erasmus, and Kirk, M. Z.: Kan. Univ. Quart., vol. 11, p. 109. 
Lawrence. 
